Spatio-temporal characteristics and driving force of land-use change in Beijing's ecological environs—A case study of Weichang County，Hebei Province

Ecological environs of Beijing have witnessed rapid development,desertification and land degradation in the last decade and post a major threat to Beijing-Tianjin eco-region.Taking Weichang County of Hebei Province as a case,the paper illustrated spatial-temporal characteristics of land-use change by construction of mathematical index and analysis of social policy effects on land-use change and industrial structure adjustment under ecological construction.The results show great change in land resource from 1992 to 1998 with a gradual reduction in cultivated land.However,from 1998 to 2002,the changes in land resource are gradual,while cultivated land decreases sharply with rapid increase in orchard lands.From 1992 to 1998,the main changes in land-use type are from grassland and uncultivated land to forest land;while from 1998 to 2002,with the exception of the changes above,transformation from cultivated land to forest land increases markedly.Diversity in land-use tends decreases as well.Human effect driven by national ecological construction policy is the rationale behind land-use changes in Weichang County.Agricultural structural adjustment,especially the return from cultivated lands to forestlands or,in recent years,to grasslands is the reason for the decrease in cultivated lands.